Variable scope and lifetime: Correct Solution

Given the following code:

public class Vesh {
    public void pemast(int e) {
        A
        int li = 0;
        mera += e;
        icol += e;
        li += e;
        System.out.println("mera=" + mera + "  icol=" + icol + "  li=" + li);
    }

    private int icol = 0;
    private static int mera = 0;

    public static void main(String[] args) {
        Vesh v0 = new Vesh();
        B
        Vesh v1 = new Vesh();
        v0.pemast(1);
        v1 = new Vesh();
        v1.pemast(10);
        v0.pemast(100);
        v0 = v1;
        v1.pemast(1000);
        C
    }
}
  1. What does the main method print?
  2. Which of the variables [li, mera, icol, v0, v1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    li=1  mera=1  icol=1
li=11  mera=10  icol=10
li=111  mera=101  icol=100
li=1111  mera=1010  icol=1000

  2. In scope at A : li, mera, icol

  3. In scope at B : li, v0, v1

  4. In scope at C : li

Explanation (which you do not need to write out in your submitted solution):

  1. li is a static variable, mera is an instance variable, and icol is a local variable.

  2. At A , v0 and v1 out of scope because they are local to the main method.

  3. At B , mera is out of scope because it is an instance variable, but main is a static method. icol is out of scope because it is local to pemast.

  4. At C , v0 and v1 are out of scope because they are not declared yet. mera is out of scope because it is an instance variable, but main is a static method. icol is out of scope because it is local to pemast.

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